sw.js

// Comic Tracker PWA Service Worker v6
const CACHE_NAME = 'comic-tracker-v6b-cache';
const ASSETS_TO_CACHE = [
  './',
  './index.html',
  './manifest.json',
  './icon-192.png',
  './icon-512.png',
  'https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=Playfair+Display:wght@700;800&display=swap'
];

// Install: cache core assets
self.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open(CACHE_NAME).then(function(cache) {
      return cache.addAll(ASSETS_TO_CACHE);
    }).then(function() {
      return self.skipWaiting();
    })
  );
});

// Activate: clean up old caches
self.addEventListener('activate', function(event) {
  event.waitUntil(
    caches.keys().then(function(cacheNames) {
      return Promise.all(
        cacheNames.filter(function(name) {
          return name !== CACHE_NAME;
        }).map(function(name) {
          return caches.delete(name);
        })
      );
    }).then(function() {
      return self.clients.claim();
    })
  );
});

// Fetch: network-first for API calls, cache-first for static assets
self.addEventListener('fetch', function(event) {
  var url = new URL(event.request.url);

  // Network-first for API calls and CORS proxy
  if (url.hostname === 'corsproxy.io' || url.hostname === 'comicvine.gamespot.com') {
    event.respondWith(
      fetch(event.request).catch(function() {
        return new Response(JSON.stringify({ error: 'offline', results: [] }), {
          headers: { 'Content-Type': 'application/json' }
        });
      })
    );
    return;
  }

  // Cache-first for Google Fonts (font files)
  if (url.hostname === 'fonts.gstatic.com') {
    event.respondWith(
      caches.match(event.request).then(function(cached) {
        if (cached) return cached;
        return fetch(event.request).then(function(response) {
          if (response.ok) {
            var clone = response.clone();
            caches.open(CACHE_NAME).then(function(cache) {
              cache.put(event.request, clone);
            });
          }
          return response;
        });
      })
    );
    return;
  }

  // Stale-while-revalidate for Google Fonts CSS
  if (url.hostname === 'fonts.googleapis.com') {
    event.respondWith(
      caches.match(event.request).then(function(cached) {
        var fetchPromise = fetch(event.request).then(function(response) {
          if (response.ok) {
            var clone = response.clone();
            caches.open(CACHE_NAME).then(function(cache) {
              cache.put(event.request, clone);
            });
          }
          return response;
        }).catch(function() {
          return cached;
        });
        return cached || fetchPromise;
      })
    );
    return;
  }

  // Cache-first for local static assets
  event.respondWith(
    caches.match(event.request).then(function(cached) {
      if (cached) return cached;
      return fetch(event.request).then(function(response) {
        if (response.ok && event.request.method === 'GET') {
          var clone = response.clone();
          caches.open(CACHE_NAME).then(function(cache) {
            cache.put(event.request, clone);
          });
        }
        return response;
      });
    })
  );
});